1. Technical Field of the Invention
This invention relates to structured light illumination (SLI) system for three-dimensional (3D) biometric detection and in particular to systems and methods for SLI imaging and processing of biometric data for spoofing detection.
2. Description of Related Art
Biometrics is the science of measuring and analyzing biological data. In law enforcement and security fields, biometrics is used to measure and analyze human features, such as fingerprints, facial patterns, palm prints, retinas, etc. Currently, binary or two-dimensional fingerprint images are the most relied upon biometric measurement for verifying a person's identity and for linking persons to a criminal history and for background checks. Criminal justice agencies rely on binary fingerprint images for positive identification to latent prints collected as evidence at crime scenes and in processing persons through the criminal justice system.
The National Institute of Science and Technology (NIST) and the American National Standards Institute (ANSI) supports the ANSI/NIST-ITL 1-2000 Data Format for the Interchange of Fingerprint, Facial, & Scar Mark & Tattoo (SMT) Information. This standard defines the content, format, and units of measurement for the exchange of biometric image information, such as fingerprint, palm print, facial/mug shot, and scar, mark, & tattoo (SMT) image information that may be used in the identification process of a subject. The information consists of a variety of mandatory and optional items, including scanning parameters, related descriptive and record data, digitized fingerprint information, and compressed or uncompressed images. This information is intended for interchange among criminal justice administrations or organizations that rely on automated fingerprint and palm print identification systems or use facial/mug shot or SMT data for identification purposes. Other organizations have different standards as well for the content, format or units of measurement for biometric information. The fingerprint and palm-print images meeting specified NIST and ANSI standards allow for matching of print images in large databases of existing fingerprint and palm-print based records. For example, the FBI maintains an Interstate Identification Index System for fingerprints and palm prints. Currently, the biometric image information required by NIST and ANSI standards for fingerprints and palm prints includes only binary biometric images or two-dimensional coordinates of fingerprint features.
In addition, the most common methods of finger print and palm print acquisition collect two-dimensional biometric images. One method is a rolled ink print technique wherein a trained technician manipulates a person's finger or hand on paper to capture an ink print that meets industry standards. Another method is electronic scanning of a finger or palm as it contacts a surface to generate a two-dimensional (2D) binary or gray scale image.
Systems are currently being developed for acquiring biometrics using 3D imaging techniques. Recent advancements in the fields of computing hardware and software have made capturing 3D biometric data a more practical solution. For example, one method of capturing 3D biometric image data is described in U.S. Pat. No. 8,224,064, entitled System and Method for 3D Imaging using Structured Light Illumination, which is incorporated by reference herein. Another example of capturing 3D biometric image data is described in U.S. patent application Ser. No. 12/991,405 entitled System and Method for Structured Light Illumination with Frame Subwindows, which is incorporated by reference herein. Another example of capturing and processing 3D biometric image data is described in U.S. patent application Ser. No. 12/717,347 entitled System and Method for Three-dimensional Biometric Data Feature Detection and Recognition, issued as U.S. Pat. No. 8,391,590 and which is incorporated by reference herein.
There is a current need for improvement in SLI systems for capturing 3D biometric images by including anti-spoofing techniques to detect use of fake biometrics.